Western blot using Rif1 polyclonal antibody ( Cat # PAB10275 ) shows detection of a band ~ 265 kDa corresponding to mouse Rif1 ( arrowhead ). Specific reactivity with this band is blocked when the antibody is pre-incubated with the immunizing peptide ( data not shown ). Approximately 25 µg of MEF whole cell lysate was separated by SDS-PAGE and transferred onto nitrocellulose. After blocking the membrane was probed with the primary antibody diluted to 1.0 µg/ml for 2 h at room temperature followed by washes and reaction with a 1:10,000 dilution of IRDyeTM800 conjugated Gt-a-Rabbit IgG [H&L] MX for 45 min at room temperature IRDyeTM800 fluorescence image was captured using the Odyssey® Infrared Imaging System developed by LI-COR. IRDye is a trademark of LI-COR, Inc.